1. Field of the Invention
The present invention relates to a manufacturing method of a coil member of a rotary electric machine such as a vehicular AC generator that is mounted on a car, a truck, or the like, a manufacturing method of a coil assembly that is an assembly of coil members each being the above one, and a manufacturing apparatus for the above coil member.
2. Description of the Related Art
The present assignee proposed a technique for increasing the mass-productivity of the above-kind of coil member of a rotary electric machine and coil assembly in U.S. Pat. No. 6,376,961 (in particular, line 58 of column 11 to line 12 of column 12, and FIG. 8). In this related art technique, a coil assembly of a rotary electric machine has a plurality of coil combinations each being a combination of two coil members. Each coil member is manufactured by turning a wire continuously. This technique can provide higher mass-productivity than in a case that many conductor segments are joined to each other.
This related art reference proposes a manufacturing method in which a plurality of wires are wound simultaneously in spiral form by using a pair of plate-like winding cores shown in FIG. 8 of the reference. Each plate-like winding core has, on the outer surface, a plurality of projections for restraining a plurality of wires. This method using such plate-like winding cores can form a plurality of (e.g., 12) coil members simultaneously by winding the same number of wires on the pair of plate-like winding cores and folding those sequentially.
However, in this related art technique, the projections that are provided on the outer surface of each of the plate-like winding cores have a fixed interval. Therefore, it is difficult to change the pitch of each of a plurality of coil members, that is, the interval between two adjoining straight portions. To adjust the length of straight portions, it is necessary to prepare plural pairs of plate-like winding cores having different widths and replace one pair with another; the length of straight portions cannot be adjusted easily either.